/Engine/Plugins/Runtime/Synthesis/Source/Synthesis/Classes/SynthComponents/SynthComponentMonoWaveTable.h
Set the Modulation depth of the Lfo controlling the Table Position around the current position value 0.0 = no modulation, 1.0 = current position +/- 0.5 (Lfo + Position result will clamp [0.0, 1.0])
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category="Synth|Components|Audio") void SetPosLfoDepth ( const float InLfoDepth )